This article has some interesting views about following large numbers of people, on Twitter.

The author, Matthew E. May, cites social media expert, Chris Brogan:

First, you don’t need to play the forced-choice, quality vs. quantity game — that if you’re in it for the people factor to connect and build relationships where there’s an exchange of value and the currency is knowledge and information — you can beat theDunbar number.

Second, to do that, there are a number of creative ways to leverage that limit. One way is to ensure that you’re in someone else’s 150 by finding the right groups of 150.